This invention relates to wire guided vehicles, such as lift trucks that are guided by wires laid in floors between storage racks. An electrical signal supplied to the wire is detected by sensor coils carried by the vehicle.
The amplitude of this signal is compared to a reference to provide information concerning the distance of the sensor coil from the wire.
The sensor coils also detect noise from many sources, such as from the contactors, motor controllers, and other electrical components in the lift truck itself, machinery operating in the building, and so forth. Obviously, this noise will degrade the ability of the circuits associated with the sensor coils and can cause errors leading to unstable directional control.